In the area of medical technology it is a common detection method to test the characteristics of certain body-specific substances or tissue parts by mixing them with suitable radioactive substances or by enriching them with radioactive materials. For the efficient evaluation of such samples, they are placed into receptacles, such as bulbs, test tubes or other recesses such as, for example, micro-titrating plates. One difficulty associated with this technique lies in the fact that the samples cover the bottom of these recesses and therefore are at least a few millimeters distant from the free surface which is accessible to a detector. In particular, in connection with the use of radioactive substances which emit only low-energy ionizing radiation, this spatial arrangement impairs the detection sensitivity of the detector, because it is not possible to bring the entrance plane of the detector sufficiently close to the respective substances. Very often tritium and J125 markers are used in these cases, in particular in connection with receptor assays.
These tests are often made for hundreds of thousands of samples by means of a liquid scintillation counter, which requires considerable time and effort.